I’m learning that every aspect of engineering a transportation device has to be considered carefully. My Refugee Travois looks simple, but boy oh boy, the devil is in the details.
Choosing the right wheels has been one of those details. After considering many different options, including wheels used on various types of carts in Africa, I finally found the Marathon Flat-Free Utility Cart Wheel, which is perfect for the travois. The president of Marathon was so excited when he heard about my project that he is sending me the wheels for free! They will arrive on Thursday!
Another detail that looks simple, but is not, is the choice of joints. I have looked at many different ways of joining the base of the travois to the main struts. Finding the optimal design has been a challenge because it needs to be strong, not too heavy, not costly, and easy for a refugee to assemble. It also needs to incorporate – or at least take into consideration – the fixture of the axle to the bottom cross beam.
After considering many options, I came up with the best two. I visited Custom Steel Inc., located in Durham, to investigate the viability of producing the joint. While I was there, talking to the metal workers about the characteristics of my joint design, I came to the conclusion that I would have to make the joints out of a thin plate of steel. I also realized that there were other kinks in the design due to limitations of modern machinery, but I figured out solutions to them. The guys at Custom Steel are great to deal with.
Labor Day Weekend is truly going to be a weekend of labor for me! Now that I have the wheels and the metal fabricator lined up, I can finally start building my prototype.